Knowledge Base Article # Q200312

Summary

The manufacturing and test of avionics products for military and commercial aircraft presents a unique set of requirements and challenges. A common test platform and consolidation of test resources facilitates development and long-term support of complex, high-value assemblies.

Manufacturers of avionics products are constantly challenged to develop, manufacture, and maintain / service a diverse range of avionics products, including aircraft data acquisition and recording systems, navigation / communication solutions and aircraft network systems. These types of products which are deployed on virtually all commercial aircraft in operation today require rigorous functional testing as well as a robust test data collection system to ensure overall system reliability and traceability. Additionally, the long product life cycles for avionics products (typically more than 20 years for service and support) requires that the associated test systems be maintained and supported which can be both technically and financially challenging.

Teledyne Controls manufactures a broad product line of avionics products which include:

1. The enhanced Digital Flight Data Acquisition Unit (eDFDAU) and Network File Server 2 (NFS2) which are installed on all Boeing 737 MAX and many Next-Generation 737 aircraft. 2. The Flight Data Interface and Management Unit (FDIMU) is deployed on most Airbus commercial aircraft and performs flight data acquisition and aircraft condition monitoring functions.3. The Wireless Quick Access Recorder (WQAR) is certified for use on most commercial aircraft and performs data recording and the wireless transfer of recording data to ground stations using a cellular network.4. The Aircraft LAN System (AirLAN), is a Wi-Fi and cellular wireless network which also supports an ARINC 429 interface and an Ethernet enabled airborne LAN unit.

Figure 1: Teledyne Avionics Products

To address the test requirements associated with these products Teledyne test engineers adopted the PXI platform as the core platform for their manufacturing test solution. Offering a broad variety of instrumentation and providing test engineers with the flexibility to build and easily reconfigure a compact, small foot print test system (see Figure 2), Teledyne selected Marvin Test Solutions’ GX7100 PXI chassis, instrumentation and ATEasy® software to provide the basis for their manufacturing test systems. With over 95 test systems deployed for both production and service applications, Teledyne has been able to address both current and future generation products using a common core system (see Figure 3).

System ConfigurationKey components of the system include a 3U/6U PXI chassis configuration (see Figure 4) which offers the flexibility to incorporate both PXI and cPCI 3U and 6U instruments while only requiring 4U of rack space. In addition, since many specialized communication bus interface cards that support the ARINC 429 and MIL-STD 1553 busses are typically available in the 6U form factor, the selection of a “combo” PXI chassis meets the requirement to support 6U cards without requiring an additional chassis. Other key components of the platform include switching, analog measurement, a high voltage (-10 to +32 VDC) source, user power and the ability to exercise multiple channels concurrently.

Figure 4: PXI Chassis with Modules Installed

System SoftwareFor manufacturers like Teledyne, the development and deployment of a modern software test environment is just as important as the ATE hardware. Besides supporting the control and monitoring of the test system’s resources, the software test environment needs to support centralized test program distribution, as well as a centralized data collection system that can interface to both a Failure Reporting and Corrective Action System (FRACAS) and reliability engineering. Other specific features of the software environment include the following requirements:

Open architecture for supporting a variety of T&M control interfaces, including PXI, IEEE, USB, ARINC 717 / 429, Ethernet, etc.

Test development environment that supports interfacing to a variety of application development environments, including textual and graphical based languages

Structured software architecture that includes a test executive and standardized framework that promotes quick development and reuse of test code

High level of reusability for predefined test procedures/sequences

Minimal programming skills required for test development

Integrated tool set for easily creating UIs for applications

Ability to manage different classes of users and assign different privileges to users based on their level of training and responsibilities

Based on the requirements detailed above, a test environment was selected that could offer the functionality and features of both a test executive and a test language. MTS’ ATEasy test executive (see Figure 5) satisfied all of the “non-test” requirements such as data logging, archiving / management of programs, and management of users while the test language offered a development environment which was T&M centric – simplifying program development and deployment. Additionally, with the open architecture of the test development environment, incorporating various instrument control interfaces such as PXI and GPIB was easily accommodated. Marvin Test Solutions’ ATEasy Test Executive and Test Development software met Teledyne’s requirements and facilitated the development of a standardized test software environment for the Teledyne platform as well as providing the ability to reuse measurement routines and procedures without modification - facilitating the development and deployment of new tests.

Figure 5: ATEasy Test Executive UI

SUMMARYPrevious generations of test stations based on custom or proprietary architectures would have taken years to develop, but by selecting a commercial off the shelf (COTS) platform as the core component, Teledyne Controls was able to complete the system design in a few months. And by standardizing on a core platform, Teledyne has been able to leverage the current platform over a 10 year timeframe, supporting over 25 avionics systems, 15 circuit card assemblies, and numerous types of UUTs – demonstrating the robustness and longevity of the platform. Currently there are over 95 test systems deployed for test and maintenance of Teledyne Controls products. In addition, by standardizing not only on a hardware platform but also on an integrated test executive and test development software platform, the development and deployment of multiple test solutions has resulted in a significant increase in test program development productivity with an equally significant reduction in test program deployment time when compared to previous generation systems. Teledyne’s experience with defining, developing and deploying a common test platform has shown that significant savings can be realized for both development and test maintenance costs.